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<TITLE>[Chapter 23] 23.12 java.beans.PropertyChangeEvent (JDK 1.1)</TITLE>
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<h2 CLASS=sect1><A CLASS="TITLE" NAME="JNUT2-CH-23-SECT-12">23.12 java.beans.PropertyChangeEvent (JDK 1.1)</A></h2>

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<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-23-SECT-12.1"></A></h3>
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<P CLASS=para>
The <tt CLASS=literal>PropertyChangeEvent</tt> class is a subclass of
<tt CLASS=literal>java.util.EventObject</tt>.  An event of this type is
sent to interested <tt CLASS=literal>PropertyChangeListener</tt> objects
whenever a Java bean changes a "bound" property, or whenever
a <tt CLASS=literal>PropertyEditor</tt> or <tt CLASS=literal>Customizer</tt> changes a
property value.  A <tt CLASS=literal>PropertyChangeEvent</tt> is also sent
to registered <tt CLASS=literal>VetoableChangeListener</tt> objects when a
bean attempts to change the value of a "constrained"
property.

<P CLASS=para>
When creating a <tt CLASS=literal>PropertyChangeEvent</tt>, you normally
specify the bean that generated the event, the programmatic
(locale-independent) name of the property that changed, and
the old and new values of the property.  If the values cannot
be determined, <tt CLASS=literal>null</tt> should be passed instead.
If the event is a notification that more than one property
value changed, the name should also be <tt CLASS=literal>null</tt>.

<P CLASS=para>
While Java beans must generate and send
<tt CLASS=literal>PropertyChangeEvent</tt> objects, it is typically only
application builders and similar tools that are
interested in receiving them.

<DIV CLASS=screen>
<P>
<PRE>
public class <tt CLASS=literal>PropertyChangeEvent</tt> extends EventObject {
    // <tt CLASS=literal>Public Constructor</tt>
            public <tt CLASS=literal>PropertyChangeEvent</tt>(Object <tt CLASS=literal>source</tt>, String <tt CLASS=literal>propertyName</tt>, Object <tt CLASS=literal>oldValue</tt>, Object <tt CLASS=literal>newValue</tt>);
    // <tt CLASS=literal>Public Instance Methods</tt>
            public Object <tt CLASS=literal>getNewValue</tt>();
            public Object <tt CLASS=literal>getOldValue</tt>();
            public Object <tt CLASS=literal>getPropagationId</tt>();
            public String <tt CLASS=literal>getPropertyName</tt>();
            public void <tt CLASS=literal>setPropagationId</tt>(Object <tt CLASS=literal>propagationId</tt>);
}
</PRE>
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<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-23-SECT-12.2">Hierarchy:</A></h3>

<P CLASS=para>
Object->EventObject(Serializable)->PropertyChangeEvent

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<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-23-SECT-12.3">Passed To:</A></h3>

<P CLASS=para>
PropertyChangeListener.propertyChange(), 
PropertyVetoException(), 
VetoableChangeListener.vetoableChange()

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<h3 CLASS=sect2><A CLASS="TITLE" NAME="JNUT2-CH-23-SECT-12.4">Returned By:</A></h3>

<P CLASS=para>
PropertyVetoException.getPropertyChangeEvent()

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